[sync] "TwoClientBookmarksSyncTest.Sanity" is flaky

chrome/browser/sync/test/integration/bookmarks_helper.h

Index: chrome/browser/sync/test/integration/bookmarks_helper.h
diff --git a/chrome/browser/sync/test/integration/bookmarks_helper.h b/chrome/browser/sync/test/integration/bookmarks_helper.h
index ae9fd7f8d60ed7669c4e60ec183616d142f9025f..115de8efbab86fe4b83260adc27997bbc7c13a98 100644
--- a/chrome/browser/sync/test/integration/bookmarks_helper.h
+++ b/chrome/browser/sync/test/integration/bookmarks_helper.h
@@ -227,6 +227,16 @@ class BookmarksMatchChecker : public MultiClientStatusChangeChecker {
   std::string GetDebugMessage() const override;
 };
 
+// Checker used to block until bookmarks match the verifier bookmark model.
+class BookmarksMatchVerifierChecker : public MultiClientStatusChangeChecker {
+ public:
+  BookmarksMatchVerifierChecker();
+
+  // StatusChangeChecker implementation.
+  bool IsExitConditionSatisfied() override;
+  std::string GetDebugMessage() const override;
+};
+
 // Checker used to block until the actual number of bookmarks with the given
 // title match the expected count.
 // TODO(pvalenzuela): Remove this class and instead use